summaryrefslogtreecommitdiff
path: root/src/binfmt/binfmt.c
blob: aa9d811f2e9d2769a2786bd3903405c93bc8d48f (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
/* SPDX-License-Identifier: LGPL-2.1+ */

#include <errno.h>
#include <getopt.h>
#include <limits.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include <sys/types.h>

#include "alloc-util.h"
#include "conf-files.h"
#include "def.h"
#include "fd-util.h"
#include "fileio.h"
#include "log.h"
#include "main-func.h"
#include "pager.h"
#include "path-util.h"
#include "pretty-print.h"
#include "string-util.h"
#include "strv.h"

static bool arg_cat_config = false;
static PagerFlags arg_pager_flags = 0;

static int delete_rule(const char *rule) {
        _cleanup_free_ char *x = NULL, *fn = NULL;
        char *e;

        assert(rule);
        assert(rule[0]);

        x = strdup(rule);
        if (!x)
                return log_oom();

        e = strchrnul(x+1, x[0]);
        *e = 0;

        if (!filename_is_valid(x + 1))
                return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
                                       "Rule file name '%s' is not valid, refusing.", x + 1);

        fn = path_join("/proc/sys/fs/binfmt_misc", x+1);
        if (!fn)
                return log_oom();

        return write_string_file(fn, "-1", WRITE_STRING_FILE_DISABLE_BUFFER);
}

static int apply_rule(const char *rule) {
        int r;

        (void) delete_rule(rule);

        r = write_string_file("/proc/sys/fs/binfmt_misc/register", rule, WRITE_STRING_FILE_DISABLE_BUFFER);
        if (r < 0)
                return log_error_errno(r, "Failed to add binary format: %m");

        return 0;
}

static int apply_file(const char *path, bool ignore_enoent) {
        _cleanup_fclose_ FILE *f = NULL;
        int r;

        assert(path);

        r = search_and_fopen(path, "re", NULL, (const char**) CONF_PATHS_STRV("binfmt.d"), &f);
        if (r < 0) {
                if (ignore_enoent && r == -ENOENT)
                        return 0;

                return log_error_errno(r, "Failed to open file '%s': %m", path);
        }

        log_debug("apply: %s", path);
        for (;;) {
                _cleanup_free_ char *line = NULL;
                char *p;
                int k;

                k = read_line(f, LONG_LINE_MAX, &line);
                if (k < 0)
                        return log_error_errno(k, "Failed to read file '%s': %m", path);
                if (k == 0)
                        break;

                p = strstrip(line);
                if (isempty(p))
                        continue;
                if (strchr(COMMENTS, p[0]))
                        continue;

                k = apply_rule(p);
                if (k < 0 && r == 0)
                        r = k;
        }

        return r;
}

static int help(void) {
        _cleanup_free_ char *link = NULL;
        int r;

        r = terminal_urlify_man("systemd-binfmt.service", "8", &link);
        if (r < 0)
                return log_oom();

        printf("%s [OPTIONS...] [CONFIGURATION FILE...]\n\n"
               "Registers binary formats with the kernel.\n\n"
               "  -h --help             Show this help\n"
               "     --version          Show package version\n"
               "     --cat-config       Show configuration files\n"
               "     --no-pager         Do not pipe output into a pager\n"
               "\nSee the %s for details.\n"
               , program_invocation_short_name
               , link
        );

        return 0;
}

static int parse_argv(int argc, char *argv[]) {
        enum {
                ARG_VERSION = 0x100,
                ARG_CAT_CONFIG,
                ARG_NO_PAGER,
        };

        static const struct option options[] = {
                { "help",       no_argument, NULL, 'h'            },
                { "version",    no_argument, NULL, ARG_VERSION    },
                { "cat-config", no_argument, NULL, ARG_CAT_CONFIG },
                { "no-pager",   no_argument, NULL, ARG_NO_PAGER   },
                {}
        };

        int c;

        assert(argc >= 0);
        assert(argv);

        while ((c = getopt_long(argc, argv, "h", options, NULL)) >= 0)

                switch (c) {

                case 'h':
                        return help();

                case ARG_VERSION:
                        return version();

                case ARG_CAT_CONFIG:
                        arg_cat_config = true;
                        break;

                case ARG_NO_PAGER:
                        arg_pager_flags |= PAGER_DISABLE;
                        break;

                case '?':
                        return -EINVAL;

                default:
                        assert_not_reached("Unhandled option");
                }

        if (arg_cat_config && argc > optind)
                return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
                                       "Positional arguments are not allowed with --cat-config");

        return 1;
}

static int run(int argc, char *argv[]) {
        int r, k;

        r = parse_argv(argc, argv);
        if (r <= 0)
                return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;

        log_setup_service();

        umask(0022);

        r = 0;

        if (argc > optind) {
                int i;

                for (i = optind; i < argc; i++) {
                        k = apply_file(argv[i], false);
                        if (k < 0 && r == 0)
                                r = k;
                }
        } else {
                _cleanup_strv_free_ char **files = NULL;
                char **f;

                r = conf_files_list_strv(&files, ".conf", NULL, 0, (const char**) CONF_PATHS_STRV("binfmt.d"));
                if (r < 0)
                        return log_error_errno(r, "Failed to enumerate binfmt.d files: %m");

                if (arg_cat_config) {
                        (void) pager_open(arg_pager_flags);

                        return cat_files(NULL, files, 0);
                }

                /* Flush out all rules */
                (void) write_string_file("/proc/sys/fs/binfmt_misc/status", "-1", WRITE_STRING_FILE_DISABLE_BUFFER);

                STRV_FOREACH(f, files) {
                        k = apply_file(*f, true);
                        if (k < 0 && r == 0)
                                r = k;
                }
        }

        return r;
}

DEFINE_MAIN_FUNCTION(run);